That article is so full of assumptions and faulty conclusions, it's astounding it was published in a professional journal of repute!
For instance:
Instead, logic suggests that the factors that determine whether to continue exertion, or to withdraw and become inactive, would be motivational.
"logic suggests"? Hardly a scientifically devised opinion!
It is not difficult to envisage the motivational factors which might restrain the surgical patient. Indeed, psychological states that inhibit behaviour in response to stress are well known. In depression, the individual does not wish to move; in anxiety he is too frightened to move. Therefore the onset of fatigue after an operation may indicate the presence of anxiety and depression at this time as it does in other clinical conditions. We would expect, therefore, measures of postoperative fatigue to correlate with those of anxiety or depression.
"to envisage", "We would expect"??
the patients who are most fatigued postoperatively were those who reported most fatigue before surgery
:DOH:A wild assumption!
Differences in psychological factors could explain why fatigue occurs after abdominal surgery but not major joint arthroplasty; whereas the former generally signifies a threat to well-being or longevity, arthroplasty is usually performed to improve well-being.
All evidence to the contrary notwithstanding!
Animals recover rapidly after surgical or other injury, apparently requiring no convalescence. For example, greyhounds can return to racing three weeks after hysterectomy.
Nothing to do with the fact that dogs have no preconception of the surgery, nor that a dog's uterine:body volume is minuscule in comparison to humans and the modus operandi of the surgery is totally different.